Vitamin D and Ivermectin are safe, effective and protect against all variants of SARS-CoV-2

The page below, and is as it was  6th April 2021, a month I first made it.   It is a response to a statement that vitamin D and ivermectin were "orphan" treatments for COVID-19.

While this may be of interest, the most important material below on vitamin D is covered better in this page:

which is a May 2022 submission to a UK government department's request for evidence regarding vitamin D, signed by Patrick W. Chambers MD (retired, Hawaii) and myself.

For the latest information on ivermectin, please see:

several articles by Pierre Kory MD (of the Front Line COVID-19 Critical Care Alliance) at:


Robin Whittle  12 May 2021
(First established 2021-04-03.  Updated intro paragraph below 2021-04-06.)

The brief title does not mean that either or both vitamin D or Ivermectin provide total protection against infection or severe symptoms, or that all variants are rendered equally non-harmful etc. with any given intake of these compounds.  I mean is that the beneficial mechanisms of vaccines - which is what most people are thinking about and relying upon - are specific to particular variants and typically do not work as well for variants with significantly different surface proteins, while the mechanisms of protection which arise from adequate vitamin D levels and judicious use of Ivermectin are are the same for all variants. This is to say that as far as I know, none of the variants' function vary in ways which specifically alter the beneficial effects of vitamin D or Ivermectin.  This is a huge advantage over vaccines.  Furthermore, whole populations can take vitamin D and Ivermectin without the need for direct medical staff involvement.

../ To the main page of this site.  Other major pages:

../01-supp/  Vitamin D3 supplemental intake quantities as a ratio of bodyweight.

../02-intracrine Illustrated explanation of how most of vitamin D's functions are performed in numerous cell types, via internal-to-the-cell intracrine signaling, which is unrelated to vitamin D's one hormonal function.

../04-calcifediol A single 1 milligram oral dose of calcifediol (now easy to obtain without prescription in the USA, Canada and Australia) will raise blood vitamin D levels (25 hydroxyvitamin D) to at least the 50ng/ml which all immune cells need to function properly (../02-autocrine/#04-quraishi) in 4 HOURS.   Ordinary D3 (5000IU/day) takes about 3 months, and even bolus 150,000IU takes ~~4 days.  Latest research at my other website.

Vitamin D and Ivermectin are not "orphan treatments"!

South African freelance health journalist Bibi-Aisha Wadvalla (2017 bio upset some MDs and advocates of both Ivermectin and vitamin D when she described both as "orphan treatments":

Covid-19: Ivermectin’s politicisation is a warning sign for doctors turning to orphan treatments
Bibi-Aisha Wadvalla,  BMJ 2021; 3732021-04-01

It is mistaken to portray doctors as not being scientists - some people are both.  Neither doctors nor scientists think alike, so there is no argument regarding who thinks best.

The BMJ generously invites Rapid Responses, which are formal comments.  RRs to this article have been submitted by MDs (both retired) Helga Rhein and David Grimes in Northern England.

I wrote the following RR, but it seems that it was too long for the BMJ.   I have since submitted a shorter version which focuses on McGregor et al. and the Quraishi 50ng/ml observations.

Since the original RR is a good introduction to the field, I have made this web page for it.  My opinions regarding nutrition etc. count for nothing since I am an electronic technician.  You may find them interesting, but my primary purpose is to encourage you - and Bibi-Aisha Wadvalla - to read and understand the most pertinent research.

The RR is plain text with a list of references.  Here I have added links for convenience and some infographics depicting the results of research articles I cite.  Text in purple is in addition to what I submitted to the BMJ.  I have also added some links to where I discuss the cited articles and where some (behind paywalls at the journal site) can be found via Sci-Hub [WP].   I spaced out the reference links in the hope that they can be selected on a touch-screen cellphone or tablet.

Quick intro to the most pertinent research regarding vitamin D, the immune system, COVID-19, Kawasaki disease etc.

Low vitamin D levels drive COVID-19 and Kawasaki disease severity

Vitamin D and ivermectin cannot reasonably be characterised as "orphan treatments" for protecting against severe COVID-19 and for suppressing disease intensity, viral shedding and so overall rates of community transmission.  There is a plethora of evidence for their effectiveness and few, if any, reports of adverse affects when used correctly.  Reports of people being harmed by self-administered veterinary ivermectin are a strong argument for MDs being able to prescribe pharma-grade ivermectin.

In addition to the cited work of Paul Marik, Pierre Kory et al. on ivermectin, the anonymous but professionally executed meta-analysis site is a good resource for people seeking the latest research.

Like ivermectin, vitamin D requires no direct involvement of medically trained staff and so can scale to whole populations far more easily than vaccines.   Both are inexpensive, very well researched and protect against all variants of SARS-CoV-2.  As an essential nutrient, vitamin D is more important still.  It can best be obtained through supplementation, since no food contains significant quantities of it, all-year round UV-B skin irradiation is unavailable to most people, pigmented skin reduces cutaneous D3 synthesis and all such UV-B exposure increases the risk of skin cancer. 

25-hydroxyvitamin D (25OHD) levels such as 20 to 30ng/ml (50 to 75nmol/L) are sufficient for the kidneys to maintain the very low levels of circulating 1,25-dihydroxyvitamin D (1,25OHD) required for regulating calcium-bone metabolism.  This is the one hormonal function of the vitamin D compounds and does not affect immune cells. 

Immune cells consume 25OHD when their autocrine (inside the cell) and paracrine (to nearby cells) signaling systems are activated[01,         02].   These systems are crucial to the each cell's ability to responds to its changing circumstances. This locally produced 1,25OHD is not a hormone.  It functions as an autocrine and or paracrine agent, at much higher levels than circulating, hormonal, 1,25OHD. 

It seems that many MDs do not understand vitamin D autocrine / paracrine signaling and have unreasonable fears of toxicity[03] when considering the D3 supplemental quantities which are required, on average, to achieve healthy, ancestral[04 ,         05] circulating 25OHD levels of ~50ng/ml (~125nmol/L), such as 0.125mg (5000IU) per day for 70kg adults[06].  This is a gram every 22 years.

McGregor et al.'s article "An autocrine Vitamin D-driven Th1 shutdown program can be exploited for COVID-19" [07] is the most important research on the molecular mechanisms by which inadequate vitamin D levels drive the pro-inflammatory cytokine storm which causes some people to develop severe COVID-19[08].  Th1 lymphocytes from the BALF (Bronchoalveolar lavage fluid WP) of hospitalised COVID-19 patients are stuck in their initial pro-inflammatory program, and fail to respond to high levels of complement, which should cause them to switch to their anti-inflammatory shutdown program.  The complement protein is detected and initiates the vitamin D autocrine signaling system by creating both 1-alpha-hydroxylase enzyme (CYP727B1) and vitamin D receptors (VDRs) in the cytosol.

The enzyme should convert intracellular 25OHD into 1,25OHD, which binds to the VDR.  The bound complex will then migrate to the nucleus and up- and down-regulate multiple genes, which will cause the cell to switch to its shutdown program.   However, this autocrine signaling system does not work in these cells, while it does in cells from the BALF of healthy control subjects.  The sole reason for this potentially deadly failure is inadequate 25OHD.

There has been no direct measurement of the circulating 25OHD level which, by diffusion to tissues, enables immune cell autocrine / paracrine signaling to proceed at full speed, to completion.  It is clear from numerous observational and intervention trial research articles, such as those analysed at, that higher circulating 25OHD levels are strongly protective against severe COVID-19 symptoms.  High levels properly facilitate autocrine / paracrine signaling in all immune cells, enabling strong direct anti-viral innate and adaptive responses, as well as ensuring proper function of Th1 and other regulatory cells to reduce or eliminate self-destructive overly-inflammatory responses.

The most direct measurement I am aware of concerns a large survey of bariatric surgery patients and the relationship between their pre-operative 25OHD levels and both surgical wound site infections and other hospital acquired infections[09].  The infection rates drop precipitously with increasing 25OHD levels and reach their minimum at 50 to 55ng/ml and above. 

Since immune cells' reliance on vitamin D is all through consuming circulating 25OHD to drive their autocrine / paracrine signaling systems, it is reasonable to conclude from this research that 55ng/ml or so is sufficient for all these cells to function well, at least regarding their 25OHD requirements.  The fact that these patients were all morbidly obese (the operations were for weight-loss surgery) does not mean the results can necessarily be extrapolated to people not suffering from obesity.  However, many people are, so this circa 50ng/ml figure, supported by many researchers, such as this recent review[10], should be regarded as a healthy target for all people, for general health and for protection against severe COVID-19.

Yet in the UK, most people cannot attain even 30mg/ml in winter, and some never attain it at any time of the year[11,         12,         13].

Higher population average 25OHD levels in the UK summer of 2020 provide the most convincing explanation for the mid-year nadir in COVID-19 infection, hospitalisation and death rates.  Summer UV-B also inactivates viruses in outdoor aerosols and on surfaces, but this is unlikely to be a major cause of low R0 since most transmission occurs inside buildings and vehicles.  Seasonal temperature and humidity variations are sometimes regarded as important determinants of viral transmission, but the seasonal outdoors variations are typically reversed by heating and air conditioning in the buildings and vehicles in which people spend most of their time in close contact with others.

MDs should be familiar with the 2015 research of Stagi et al.[14] in which children suffering from the extreme immune dysregulation condition of Kawasaki disease were found to have average 25OHD levels of 9.2ng/ml.  Those with coronary artery abnormalities averaged only 4.9ng/ml

Vanegas-Cedillo et al.[15] provide a graph of COVID-19 death hazard ratio which rises dramatically with lower 25OHD levels.  Tuncay at al.[16] report average 25OHD levels of 36.2ng/ml for healthy controls, and for COVID-19 patients:  21.2ng/ml non-severe; 14.6ng/ml severe and 10.5ng/ml for those who died.

All the clinical evidence and mechanistic research points to circulating 25OHD levels below about 50ng/ml being causatively associated with worse outcomes for COVID-19 and numerous other conditions.  While inflammatory conditions probably do reduce 25OHD levels somewhat - making pre-infection 25OHD levels a more reliable indication of initial vitamin D sufficiency than those taken mid-illness - this inflammatory loss of 25OHD is a further argument for rapid interventions to raise these levels.

Unfortunately, many clinicians first encounter the problems of low vitamin D levels when their patients are already seriously ill or on the brink of becoming so.

In such clinical emergencies vitamin D3 supplementation is of marginal use.  Bolus D3 such as several hundred thousand IU for adults may be helpful, but it takes days to a week or so for this to be converted in the liver to the circulating 25OHD the patient's immune cells urgently need.

The only way 25OHD levels can be raised substantially within hours is with calcifediol, the pharmaceutical name for 25OHD.  In the Cordoba calcifediol RCT of Castillo et al.[17] just 0.532mg oral calcifediol, given at the earliest opportunity to hospitalised COVID-19 patients, reduced ICU admissions from 50% to 2% and deaths from 8% to zero.   No 25OHD measurements were taken, but the initial rise in 25OHD levels can be estimated from a graph in a patent for the same Faes Farma Hidroferol capsules as used in the trial[18].  In young, healthy and presumably non-obese control subjects, average levels rose from 18ng/ml at baseline to 63ng/ml or more between 4 and 12 hours after ingestion, dropping slowly to about 45ng/ml after three days, when follow-up 0.266mg calcifediol was administered.

Long-term, robust, D3 supplementation is they key to preventing the worst outcomes of COVID-19 - and likely suppressing viral shedding and so overall levels of community transmission.  However oral calcifediol may be the closest thing there is to a magic bullet for emergency COVID-19 intervention, though Pierre Kory et al. report similarly beneficial effects with ivermectin.   Both treatments are effective and safe, and I am not aware of any reasons why they should not be combined.

The quantity of calcifediol required is very small, and daily D3 supplementation following this should be sufficient to maintain the raised 25OHD levels.  However, calcifediol may be difficult to obtain.  Recently, Dutch nutritional supplement giant DSM released small (150mg) tablets containing 10mcg in Australia, without need for prescription: .  An inexpensive bottle of 60 of these contains about the same amount of calcifediol as the two capsules which in Cordoba saved many people from harm and death.

Vitamin D deficiency is recognised as a national problem in sunny Pakistan, where a Vitamin D Academy has been established[19].  220 MDs, PhDs and professors from all over the world signed an Open Letter calling for all nations to robustly supplement their populations.  Most of these signatories recommended 4000IU/D3 a day and many take more than this themselves[20]. (They were given the option of recommending 0.05mg 2000IU or 0.1mg 4000IU D3 a day for adults.)

The UK government's 0.01mg 400IU D3 per day recommendation is barely enough to ensure bone health, and a tenth or less of what is needed to properly supply the immune system with 25OHD.  This is a gram every 274 years, and D3 costs £2 a gram ex-factory.

01 Hewison M. Antibacterial effects of vitamin D. Nat Rev Endocrinol 7, 337–345 (2011). (Paywalled.) 
339 Google citations.  Discussed at:

02 Whittle R. Vitamin D autocrine signaling - illustrated explanation.

03 Holick MF. Vitamin D Is Not as Toxic as Was Once Thought: A Historical and an Up-to-Date Perspective. Mayo Clin Proc.nMay 2015;90(5):561-564

04 Charoenngam N, Holick MF. Immunologic Effects of Vitamin D on Human Health and Disease. Nutrients. 2020; 12(7):2097.

05 Luxwolda MF, Kuipers RS, Kema IP, Dijck-Brouwer DA, Muskiet FA. Traditionally living populations in East Africa have a mean serum 25-hydroxyvitamin D concentration of 115 nmol/l. Br J Nutr. 2012 Nov 14;108(9):1557-61.

06 Ekwaru JP, Zwicker JD, Holick MF, Giovannucci E, Veugelers PJ (2014) The Importance of Body Weight for the Dose Response Relationship of Oral Vitamin D Supplementation and Serum 25-Hydroxyvitamin D in Healthy Volunteers. PLoS ONE 9(11): e111265.  Discussed at:

07 McGregor R, Chauss D et al. An autocrine Vitamin D-driven Th1 shutdown program can be exploited for COVID-19. bioRxiv preprint. 2020-07-19  Summarised and discussed at:

08 Marik PE. Critical Care COVID-19 Protocol. 2020-12-07

09 Quraishi SA, Bittner EA, Blum L, Hutter MM, Camargo CA. Association Between Preoperative 25-Hydroxyvitamin D Level and Hospital-Acquired Infections Following Roux-en-Y Gastric Bypass Surgery. JAMA Surg. 2014;149(2):112–118.  Discussed at:

10 Charoenngam N, Shirvani A, Holick MF. Vitamin D and Its Potential Benefit for the COVID-19 Pandemic, Endocrine Practice (2021),

11 Fig 1D in Raisi-Estabragh Z, McCracken C et al. Greater risk of severe COVID-19 in Black, Asian and Minority Ethnic populations is not explained by cardiometabolic, socioeconomic or behavioural factors, or by 25(OH)-vitamin D status: study of 1326 cases from the UK Biobank, Journal of Public Health, Volume 42, Issue 3, September 2020, Pages 451–460,

12  Darling A, Blackbourn D, Ahmadi K, Lanham-New, S. Very high prevalence of 25-hydroxyvitamin D deficiency in 6433 UK South Asian adults: Analysis of the UK Biobank Cohort. British Journal of Nutrition, 125(4), 448-459. , PDF.

13 Sutherland JP, Zhou A, Leach MJ, Elina Hyppönen. Differences and determinants of vitamin D deficiency among UK biobank participants: A cross-ethnic and socioeconomic study, Clinical Nutrition, 2020,ISSN 0261-5614.

14 Stagi S, Rigante D et al. Severe vitamin D deficiency in patients with Kawasaki disease: a potential role in the risk to develop heart vascular abnormalities?. Clin Rheumatol 35, 1865–1872 (2016).  (Paywalled.)  Discussed at:  

15 Vanegas-Cedillo PE, Bello-Chavolla OY et al. Serum Vitamin D levels are associated with increased COVID-19 severity and mortality independent of visceral adiposity.  medRxiv preprint 2021.03.12.21253490,

16 Tuncay E, Gemcioglu M et al. A notable key for estimating the severity of COVID-19: 25-hydroxyvitamin D status. Turkish Journal of Biochemistry, vol. , no. , 2021.

17 Castillo ME, Entrenas Costa ML et al. Effect of calcifediol treatment and best available therapy versus best available therapy on intensive care unit admission and mortality among patients hospitalized for COVID-19: A pilot randomized clinical study.  The Journal of Steroid Biochemistry and Molecular Biology, Volume 203, 2020, 105751.  Discussed at:

18 Sune Negre JM, Azpitarte OI et al. Calcifediol Soft Capsules WIPO WO 2016/124724 Al 2016-08-11  Discussed at: .

19 Pakistan's first 'Vitamin D Academy' inaugurated in Punjab 2021-04-02

20 Over 200 Scientists & Doctors Call For Increased Vitamin D Use To Combat COVID-19, Scientific evidence indicates vitamin D reduces infections & deaths.

Further infographics

© 2021 Robin Whittle   Daylesford, Victoria, Australia